Space above sunroom is cold, what would effective insulation be?

NIMAN

I have a small room of sorts (more a space) above my sunroom, which is used as a storage area.

At this time of year its quite cold, and I was wondering what would be a cheap way of insulating it to warm it slightly? It has a radiator in it, so would like to keep any heat in if possible.

Would something like this help at all (I won't be wallpapering over it)?
http://www.amazon.co.uk/Insulating-Polystyrene-Lining-Paper-Wallpaper/dp/B006UFLBIO/ref=sr_1_11?ie=UTF8&qid=1388982899&sr=8-11&keywords=insulation

Or would I need something more like this:
http://www.amazon.co.uk/1-2m-Ufoil-Double-Foil-Insulation/dp/B006H1MO0U/ref=sr_1_4?ie=UTF8&qid=1388983025&sr=8-4&keywords=insulation

Or even this:
http://www.amazon.co.uk/EXPANDED-POLYSTYRENE-FOAM-SHEETS-2400x1200x50mm/dp/B007BFE57G/ref=pd_sim_sbs_diy_6

Or, the expensive option:
http://www.amazon.co.uk/Xtratherm-Performance-Rigid-Insulation-Board/dp/B00CPBDZV8/ref=sr_1_13?ie=UTF8&qid=1388983068&sr=8-13&keywords=insulation

Jonny Harris

Have you looked at tri iso super 10. It seems very good
regards

NIMAN

Thanks for that.

I checked it out and it looks like stuff that would be mounted on the rafters. As mine is going to be in a room it would have to be mounted directly on to plasterboard walls, so I can not have the air gap on both sides that this stuff requires.